


Heir Apparent

by the_incidental_author



Category: Hunter X Hunter
Genre: Assassination, Child Abuse, Gen, Kid!Killua, That is not seen as child abuse because Zoldycks
Language: English
Status: Completed
Published: 2016-08-02
Updated: 2016-08-02
Packaged: 2018-07-28 20:12:13
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,585
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7655047
Author URL: https://archiveofourown.org/users/the_incidental_author/pseuds/the_incidental_author
Summary: <blockquote class="userstuff">
              <p>Why is Killua the one to inherit the family business? Out of all the middle children in the world, why is it that Killua is not only noticed, but captures his family's hopes and attention so much that even the obvious choice of heir, the eldest son, insists that he will be the one to lead their family to greater heights of infamy? Expectations like that don't just come out of nowhere.</p>
<p>One-shot about Killua's early life, and how the Zoldyck Family Dynamic(TM) came to be.</p>
            </blockquote>





	Heir Apparent

When Killua Zoldyck was born with a shock of snow-white hair on his head, Kikyo declared him the most beautiful child she had ever seen. When Silva held him for the first time and his pudgy fingers wrapped around the master assassin's long silver locks with a minuscule but surprising strength, he hid a charmed smile behind a gruff order for the midwife to attend to his wife. When Silva very carefully handed him over to his eldest son, Illumi gazed at the little bundle of cloth blankly, recalling vaguely the sensation of holding Milluki in his arms at age five, when his first brother had come into the world. Now, at age 12, the experience was much more moving, as he gazed down at the tuft of soft white hair and felt the fragile weight of a life in his arms. A life like the dozens he had already snuffed out in his training and his first few assignments.

Only this life was family. This life was meant to be protected. It was the antithesis to everything he had learned, and Illumi felt a very sudden and very unfamiliar fear – the fear that he would not succeed. That wispy white hair reminded him of the snow that fell gently on Kukuroo mountain each winter, and how it disappeared, crushed underfoot and melting instantly at the heat of his touch, no matter how hard he tried to hold on to it. When Illumi refused to hand Killua over to Milluki when the seven-year-old asked, Milluki stomped his feet, scowled up at his father, and asked "what's so great about a stupid baby, anyway?" And he would continue to feel this resentment for years to come.

*   *   *

Killua began his poison training the way all of the Zoldyck children did – through their mother's breast milk. Once they began weaning him onto solid food, however, the dosages could be increased. At 14 months, Killua was resilient enough to begin building a resistance to snake venom, and so, like every child in his family, he found himself being visited in his play-pen by a mildly venomous local viper. Kikyo and Silva observed from the shadows, ready to intervene if something went wrong, and waited. Killua watched the snake curiously as it slithered towards him, waiting to see what it would do.

The motion of the snake striking was expected. The motion of Killua's counter-strike was not. Both Kikyo and Silva were stunned into momentary inaction as they watched the baby take hold of the snake where it had latched onto one chubby leg and crush its head in a fist. When Killua let out a scream in his pain and confusion, Kikyo moved quickly and swept him up in her arms, and whispered comfort to him in hushed and reverent tones.

After Killua had killed the snake, his training was accelerated, although he had no way of knowing this. He learned to allow the snakes to bite him the way he allowed his parents to give him strange, burning shots, and break his bones. The bones would heal and be stronger than before, just like the shots would make him stronger than he was. Killua understood, more than any of the Zoldyck children had at his age, that these things were for his protection, and rather than turning him cold the way the torture had his brothers, it simply taught him how fragile people were, and how much it took to protect one. His obedience delighted his parents, and they doted on him more and more.

Illumi also understood how fragile life was, although he had learned this not in the context of protecting a life, as Killua viewed it, but in the process of ending many. A Zoldyck child was given a target whenever they were deemed capable enough to succeed – this was really the only criteria, as it was the only rule given to the various jobs the family took: a Zoldyck must never fail. Illumi had been 8 years old when he made his first kill, and although it had not gone smoothly, he had succeeded, as he must. It had taken several needles, through the eyes, throat, and temples, before Illumi had managed to end his first life. With a few more practice runs under his belt, he would eventually economize to the point of using a single needle.

When Killua was deemed ready to take his first life, he was only five years old. He had been ready, they determined, for almost a year – ever since he had, to even Silva's astonishment and Kikyo's delight, somehow mastered the Rhythm Echo. (Unknown to either of them, he had been receiving extra lessons from Illumi whenever his brother was home, since Illumi was convinced that Killua needed to be as prepared as possible to face any and all kinds of danger before he went out on his first assignment).

They had waited an extra year before sending Killua out at Zeno's insistence, deferring to the elder of the family although they suspected his decision came not from reason but protectiveness. And although the Zoldyck family would not hesitate to send any of its children into dangerous and deadly situations, Killua was, as he had been since his birth, an exception. That extra year was spent on weapons training, which was normally spread out over the time that it took to train new assassins. It was important for each child to be comfortable handling all kinds of weapons before their first job, because their choice of killing technique would help define their training from that point forward. Illumi, who had chosen his long needles, went on to study anatomy and acupuncture more intensely than almost anyone in family history had ever done. Milluki, who had quietly disabled all alarms and fire alarms, before putting a ball of aluminum foil in the microwave for an hour and leaving, had learned everything he could about hacking and programming.

Killua, when the time came to choose his weapon, left empty-handed. The same thing that had allowed torture to make Killua gentle now made him, in the eyes of his brother, reckless. Illumi tried to convince Killua to take a knife with him, but Killua held his ground.

"If I'm going to end a life, I want to know it." Killua said, his voice high-pitched but steady, and Illumi only stared at him in helpless confusion as Silva put a hand on the older boy's shoulder. Killua turned and left his family wondering, but to him it was very clear. Life was fragile, but people were willing to protect it anyway. Everyone who was alive had been protected as a baby (this Killua had realized when his turn came to hold his younger brother in his arms) and so everyone who was alive held value to someone. Enough value for them to fight a hopeless battle against that fragility.

Killua was, although his family had not yet realized it, gentle in nature. While he had no qualms about killing (where would he have gained such a moral code?) he had an innate sense of its importance. His brothers killed casually, thoughtlessly, as if their targets were not real people. Perhaps, Killua thought in some dark corner of his mind, that was what it took to be a good assassin, but the rest of him valued clarity of focus over all else.

He set eyes on his target first while the man was having dinner. Killua watched him for two days before he found an opening, and he slipped in through a window while the man was showering. He entered the bathroom unseen and came up to the shower curtain, hearing the man singing vigorously on the other side. Here, Killua paused to listen, and realized that it was a love song. Possibly related to the woman he had seen the man having dinner with the first night. Killua absorbed this with fascination, having never witnessed romantic interaction, although he had of course been taught all about it and how it may be used to his advantage during a job.

Killua felt no hesitation, no remorse, and no doubt as he slipped behind the shower curtain and broke the man's neck in a single motion. What he did feel, however, was awareness. Awareness that there was someone who would miss this man. Who would be distressed to be reminded of how fragile he had been. Because of this awareness, Killua took the body away with him to dispose of it where there was no chance of the man's lover finding it. His parents, where they were observing from afar, were delighted at his thoroughness in covering up his work – something that their other children had all developed after several jobs.

It was after Killua's first kill, where he had chosen his bare hands over any weapon, that his father began to make plans for him. First he taught Killua how to manipulate the skeletal structure of his hands to form more effective weapons – something only the heir of each generation was taught, although no one but Silva and Zeno knew this – and then he began to increase the pace of his training bit by bit until he realized, quite suddenly, that Killua had become _too_ efficient.

Silva tasked his prodigious son with mastering darts in order to buy himself some time to think, and watched as Killua deconstructed and learned the game with a ruthless efficiency. This was the problem: Killua was incredibly intelligent. His skill for strategy had even astonished Zeno, who had once been considered a genius as well as a master assassin. The boy could analyze and effectively neutralize an opponent's strengths and weaknesses without having to do much more than look at them. It was enough to make Kikyo faint with joy, but Silva saw the drawbacks as clear as day: Killua was not getting stronger. His son was so good at taking apart his opponents that he had never met with true confrontation. He had never mastered the various combination and counters that Silva had taught him, because Killua had never had to worry about a counterattack. His first hit was always a surprise, and always a killing blow.

A week after Killua had mastered darts, Silva dropped him off at heavens arena with the order to not kill any of his opponents, and to return home after he had reached the 200th floor. Silva couldn't help but smile slightly at the sight of his son's befuddled face in the rearview mirror as he was left behind. It was an odd assignment, for sure, and he knew he would have to deal with Illumi's fretting until Killua finally returned, but this would force his son to grow in spite of his talent.

When Silva returned to Kukuroo mountain, he quickly escaped to his office with the excuse of work to be done. Illumi was, as predicted, completely beside himself with worry, although he refused to acknowledge it for what it was. Kikyo was furious that Silva had made such a large decision about Killua's training without her, and on top of that had given him an assignment that did not even translate directly into assassination. Milluki, when Silva saw him, simply glared at his father balefully and pointed out that _he_ had never been sent to Heaven's Arena. Silva reminded him that he had refused to leave his room for the past four months.

Killua, meanwhile, discovered that he had absolutely no idea how to not kill people. He knew how to break them (so fragile, like candy sculptures) and how to protect them (make them strong, keep them away from anything stronger) but he had no idea how to interact with them outside of that capacity. What did people _do_ when they weren't killing each other?

On top of that, Killua was forced to stand in line and maneuver through various crowds. Killua had never been in a crowd in his life, and he was overwhelmed by how _loud_ it was to be in the midst of it all, rather than observing from the outside. Somehow, though, he was feeling... different. More something. Like the first time he had seen one of the manga that he would sometimes snatch from Milluki's room on a TV screen, moving and talking and _alive._ Killua's blue eyes were wide and his mouth hung open slightly as he took everything in. Several people leered at him, a wide-eyed six-year-old waiting in line with all of these adults, but he was too busy absorbing all of the activity around him to care.

When he got to the front, he found that the counter was above his head. He stared at it, disgruntled, and the woman at the counter looked around impatiently for the next person in line.

"Next!" She called again, and Killua decided to raise his hand, which could barely clear the counter, and wave it.

"I'm next." He said, without inflection. He wasn't sure how he was supposed to sound. Serious? Excited? He was afraid to embarrass himself on his first long-term assignment, and so he settled on indifferent.

"You're... Where are your parents, little boy?"

"Somewhere." Killua responded. "I'm here to fight in Heaven's Arena. This is where I sign up, right?"

"I... yes. Are you sure your parents are okay with you fighting?" Killua saw red hair as the receptionist craned her neck to see him and he met her eyes steadily.

"Yes." He said. "My father dropped me off."

"People can get hurt in these fights, you know." She said, and Killua finally smiled, glad she was beginning to explain the rules.

"So you can hurt people, but no killing? If torture is allowed, is the goal to get your opponent to surrender first?" There was a tense silence, and Killua tilted his head after it went on for a bit too long, wondering what was wrong. Had he asked a stupid question?

"No.. ah, that is..." The receptionist cleared her throat several times, and Killua crossed his arms impatiently. "The goal is to knock your opponent out, whether by knocking them unconscious or scoring a Technical Knock Out. The way you do that is..." Killua listened as she explained the rules, curious about the motivation behind such a tournament but seeing the benefits of being adept at knocking people unconscious without killing them; if you needed to take hostages, for instance... although if you had to resort to taking hostages, you were a poor excuse for an assassin.

Once Killua had signed his release waiver and found his way to the waiting room, he made himself comfortable on a bench in one corner and watched the other competitors, kicking his feet where they dangled less than halfway to the floor. It was strange, he thought, to be here by himself. Even on his usual jobs, he could feel his family watching him. Now there was nothing. His father had really left him to fend for himself – and with such strange rules! No killing. Killua had never left the house without killing someone before.

It was itchy. He didn't know what to do, surrounded by all these people, and none of them his target. He had seen people before, but never spoken to any outside of his family and the butlers. His targets spoke to him sometimes, although they never had much time to talk, and he had never responded to any of them. When he glanced at the man on the bench next to him, Killua found himself cataloguing and dissecting all of his weak points before he knew what he was doing. He blushed to the roots of his hair when he realized he had already found six ways to kill him.

Not a target. Not a target. Killua repeated this to himself as his number was called and he made his way to the ring for his first ever fight. Not an assassination – a fight. Not a target – an opponent. He watched the other fights happening in other rings as he waited, hoping for a hint of what he was supposed to do. He hardly noticed when the referee hesitated to call the fight to start, and it was only when his opponent approached him – slowly, as if he was also reluctant to begin the fight, did his opponent not know what he was supposed to do, either? - that he finally looked away from a pair of men who were taking turns punching each other in the face very weakly.

Killua looked at the man, who was at least three times as tall as him and several more times his weight, as he loomed uncomfortably over the little assassin. Most of the fights around them seemed to consist of hand-to-hand combat like what his father had taught him, although Killua had never had cause to use it in an assassination. Was this the sort of occasion those lessons had been preparing him for? That would make sense.

"Practically in diapers. How am I supposed to fight a kid in good conscience?" Killua blinked at the man as he turned and spoke to the referee. Killua's eyes narrowed. Diapers? Was that supposed to be him?

"I'm not in diapers. I'm six. And even if you're scared to fight me, I won't go easy on you." The man turned to look at him again, and Killua eyed the scar running across his face with disinterest. The man sighed, and waved to the referee, who called for the match to re-start. As soon as he gave permission to start, Killua climbed his way onto the man's shoulders and wrapped his legs around his neck before he had time to do much more than shift forward. Killua knew that if he applied much less pressure than he would use to deal a killing blow, he could cut off his opponent's air supply and wait until he passed out.

Not knowing how much pressure would be too much, Killua decided against directly tightening his legs, and just pointed his toes instead, causing his calves to flex slightly. The man gagged loudly, and Killua worried that he had crushed his windpipe for a moment, before the man's hands snatched him from his shoulders during his brief period of inattention. Killua's eyes widened as he was hurtled across the ring, although he managed to land on his feet.

Fighting was dangerous, Killua realized. Much more dangerous than assassination. Killua sighed, resigning himself to a slow learning process. He couldn't risk overreaching and killing one of his opponents, after all. That would be failing his assignment, and a Zoldyck always succeeds. If it came down to it, he would always choose to lose a single match over failing his assignment.

But not this match. Killua was certain that even if this man hit him with his full strength, it wouldn't be enough to knock him off his feet, much less unconscious. Relaxing at this assurance, Killua settled in for the long haul. He would continue to observe the other competitors until he learned how to use his own strength, and then he would return home when he was strong enough to show mercy.

*   *   *

This was not what Silva had expected. Killua was back, a scant two years later. Two years. Eight-years-old and he had earned the right to battle _nen-practitioners._ And Silva had the sinking feeling that his most precocious son had not even rushed – likely working at his usual steady, deliberate pace. Taking his assignment apart until he understood it completely, as he always did. The head of the Zoldyck family held back a heavy sigh.

"Did you reach the 200th floor?" He asked, knowing the answer. Killua nodded, holding out the paper that signified his achievement. "Did you kill anyone in the past two years?'

"No. I didn't even permanently damage any of them!" Silva looked down at this little slip of a boy and tried not to look as long-suffering as he felt. His son was practically vibrating with energy, clearly fascinated by his new-found restraint. _What have I done?_

"Very well. Final question. What on earth are all those boxes?"

"Choco-robots! They're _amazing._ I didn't know if I would be able to get them here, so I brought enough to last me for a couple months."

"This is only enough for a _couple months_?" Silva asked in disbelief, eyeing the stack of crates that threatened to dwarf his petite son. Killua looked confused, before he shook his head.

"No, this is just what I could carry with me. The butlers are bringing the rest of it up now."

"The rest?"

"Uh-huh. Did you know they give you money every time you win a fight? I had enough to buy out the whole factory!" Silva met happy blue eyes, realizing that Killua was very different than he had been two years ago. The Killua from before, while not hesitant to smile, had never shown any sort of enthusiasm, only a keen intelligence and obedience. Now, not only was he brimming with exuberance – he had developed a taste for fighting and sugary snacks. What had happened to his darling son who would never have expressed a preference for one thing over another? Had learning to fight without killing done this, or was it the extended time away from his family? Silva suddenly felt as if he had made a fatal mistake.

_Kikyo is going to kill me._

 

**Author's Note:**

> And there you have it. Silva, you poor, naive beefcake. You should know better than to let Killua anywhere where he might get Ideas. Those can lead to Thinking and Free Will. Your wife would be appalled. 
> 
> I like to privately think of this piece as the Killua Has Strong Hands headcanon.
> 
> Hope you enjoyed.


End file.
